Motor controller for electric blowers

A method for calibrating an electric blower system, the method comprising:

• operating an electric motor to turn a blower to generate an airflow into an airflow system defining a first system resistance;
• determining a first benchmark data point, indicating a first torque and a first speed, corresponding to the first system resistance, wherein a first airflow-to-speed ratio is constant for the first system resistance;
• adjusting the first system resistance to a second system resistance;
• determining a second benchmark data point, indicating a second torque and a second speed, corresponding to the second system resistance, wherein a second airflow-to-speed ratio is constant for the second system resistance;
• and
• generating, from at least the first and second benchmark data points, an operating profile defining torque, speed, and airflow points for different system resistances.

An airflow system comprising:

• a motor coupled to a blower configured to generate an airflow;
• and
• a motor controller coupled to said motor configured to:
• receive a first airflow demand;
• operate the motor at a first speed and a first torque to generate a first airflow;
• determine a first airflow-to-speed ratio based on the first speed and the first airflow;
• detect a change in torque or speed corresponding to a change in system resistance;
• determine a second airflow-to-speed ratio based on the changed torque or speed;
• and
• determine at least one of a second speed and second torque based on the second airflow-to-speed ratio to generate the first airflow for the changed system resistance.